State Key Laboratory of Crop Stress Biology in Arid Areas and College of Agronomy, Northwest A&F University, Yangling, 712100, Shaanxi, China.
Crop Research Institute, Key Laboratory of Wheat Biology and Genetic Improvement in North Yellow & Huai River Valley, Ministry of Agriculture/Shandong Provincial Technology Innovation Center for Wheat, Shandong Academy of Agricultural Sciences/National Engineering Research Center for Wheat & Maize, Jinan, 250100, China.
Planta. 2022 Aug 29;256(4):65. doi: 10.1007/s00425-022-03978-0.
TaATLa1 was identified to respond to nitrogen deprivation through transcriptome analysis of wheat seedlings. TaATLa1 specifically transports Gln, Glu, and Asp, and affects the biomass of Arabidopsis and wheat. Nitrogen is an essential macronutrient and plays a crucial role in wheat production. Amino acids, the major form of organic nitrogen, are remobilized by amino acid transporters (AATs) in plants. AATs are commonly described as central components of essential developmental processes and yield formation via taking up and transporting amino acids in plants. However, few studies have reported the detailed biochemical properties and biological functions of these AATs in wheat. In this study, key genes encoding AATs were screened from transcriptome analysis of wheat seedlings treated with normal nitrogen (NN) and nitrogen deprivation (ND). Among them, 21 AATs were down-regulated and eight AATs were up-regulated under ND treatment. Among the homoeologs, TaATLa1.1-3A, TaATLa1.1-3B, and TaATLa1.1-3D (TaATLa1.1-3A, -3B, and -3D), belonging to amino acid transporter-like a (ATLa) subfamily, were significantly down-regulated in response to ND in wheat, and accordingly were selected for functional analyses. The results demonstrated that TaATLa1.1-3A, -3B, and -3D effectively transported glutamine (Gln), glutamate (Glu), and aspartate (Asp) in yeast. Overexpression of TaAILa1.1-3A, -3B, and -3D in Arabidopsis thaliana L. significantly increased amino acid content in leaves, storage protein content in seeds and the plant biomass under NN. Knockdown of TaATLa1.1-3A, -3B, and -3D in wheat seedlings resulted in a significant block of amino acid remobilization and growth inhibition. Taken together, TaATLa1.1-3A, -3B, and -3D contribute substantially to Arabidopsis and wheat growth. We propose that TaATLa1.1-3A, -3B, and -3D may participate in the source-sink translocation of amino acid, and they may have profound implications for wheat yield improvement.
TaATLa1 是通过小麦幼苗的转录组分析鉴定出来的对氮饥饿作出响应的基因。TaATLa1 特异性运输 Gln、Glu 和 Asp，并且影响拟南芥和小麦的生物量。氮是一种必需的大量营养素，在小麦生产中起着至关重要的作用。氨基酸是有机氮的主要形式，在植物中通过氨基酸转运体（AATs）再循环。AATs 通常被描述为通过在植物中摄取和运输氨基酸来参与基本发育过程和产量形成的核心组成部分。然而，很少有研究报道这些 AATs 在小麦中的详细生化特性和生物学功能。在这项研究中，从用正常氮（NN）和氮饥饿（ND）处理的小麦幼苗的转录组分析中筛选出编码 AAT 的关键基因。其中，21 个 AAT 在 ND 处理下下调，8 个 AAT 上调。在同系物中，TaATLa1.1-3A、TaATLa1.1-3B 和 TaATLa1.1-3D（TaATLa1.1-3A、-3B 和 -3D）属于氨基酸转运体样 a（ATLa）亚家族，在小麦中对 ND 响应显著下调，因此被选择进行功能分析。结果表明，TaATLa1.1-3A、-3B 和 -3D 有效地在酵母中转运谷氨酰胺（Gln）、谷氨酸（Glu）和天冬氨酸（Asp）。在拟南芥中过表达 TaAILa1.1-3A、-3B 和 -3D 显著增加了 NN 下叶片中的氨基酸含量、种子中的储存蛋白含量和植物生物量。在小麦幼苗中敲低 TaATLa1.1-3A、-3B 和 -3D 导致氨基酸再循环和生长抑制的显著受阻。总之，TaATLa1.1-3A、-3B 和 -3D 对拟南芥和小麦的生长有很大的贡献。我们提出 TaATLa1.1-3A、-3B 和 -3D 可能参与氨基酸的源库转运，它们可能对提高小麦产量有深远的影响。
